1 Scope

1.1 These requirements cover direct acting (spring loaded) and pilot operated fire pump relief valves of nominal 3/4 inch (19.05 mm) size and larger, intended for use in water supply systems for fire protection service.

1.2 Requirements for the installation and use of these valves are included in the Standard for the Installation of Stationary Pumps for Fire Protection, NFPA 20.

Summary of Topics

This new edition of ANSI/UL 1478 dated March 17, 2023 includes editorial revisions to align with UL Standards & Engagement’s style manual: Titles of referenced publications were added in a new section, the Components section was updated, reference standard titles were removed from the body, and some spelling and grammar changes were made.